Progress on a broad tax extenders package could face a delay, with Sen. Tom Coburn seeking the support of his Finance Committee colleagues for 61 amendments.

A spokesman of the Oklahoma Republican said that whether a committee markup of the extensions goes forward Thursday would depend on whether Finance Chairman Max Baucus wants to allow progress on the Coburn amendments.

The Montana Democrat and Senators in both parties want to press ahead on separate legislation to extend and revive an assortment of specialized tax benefits ranging from deductions on home mortgages and state and local sales taxes to incentives for users of public transportation systems.

The package unveiled by Baucus would also keep middle-class taxpayers from being hit by the alternative minimum tax, which was designed to ensure wealthy people pay enough in taxes but can affect a much larger segment of the population without a patch.

Coburn contends that many of the extenders constitute spending through the tax code and should be scaled back or eliminated. His amendments pick apart the package.

The initial draft of the chairman’s mark left out an extension of the wind energy tax credit authored by Sen. Chuck Grassley (R-Iowa) after the presidential campaign for Mitt Romney announced the candidate’s opposition to the tax provision.

Grassley, however, said today that he thought the final tax extenders package would revive the provision.

“I believe it’s going to be accommodated, but I haven’t had enough of a discussion to answer that for sure,” Grassley said. “I believe it can be accommodated without a lot of turmoil.”

Grassley appeared to succeed in getting the wind production credit back into the measure because Coburn filed an amendment to strike it out.

Other Coburn amendments include provisions to prevent restaurant chains such as Starbucks, Subway and IHOP from claiming a tax credit and another that would keep prison inmates from claiming tax breaks.

Coburn’s amendments may not be the only obstacles.

“I’ve heard that there are about four or five people who are objecting because of the 48-hour rule to file amendments. So, I think ... it’s still up in the air the extent to which it’ll come up tomorrow,” Grassley said.

Senators on the Finance Committee have worked out the package of extensions, with lawmakers in both parties expecting it will win support from both sides of the aisle.

“We expect a resounding vote in committee on this package. The true test of whether Republicans are acting in good faith will come when this deal reaches the floor,” Sen. Charles Schumer said in a statement.

“We will be counting on Republicans to clear a procedural path for it, and not let it get bogged down by a ‘gotcha’ fight over the estate tax,” the New York Democrat added.

Grassley, a former chairman of the Finance panel, said in an interview that he suspected GOP Senators would not play games with the measure on the floor if Schumer and the Democrats did not attempt to attach other tax provisions, including those from the 2009 economic recovery law championed by President Barack Obama.

“I think we will not do that if he doesn’t try to do things that were in the stimulus bill that he’s not satisfied is in this chairman’s mark,” Grassley said. “Obviously, if he wants to bring up stuff that he likes, we ought to have the same privilege.”

Even if the measure gets through the Senate in September, House leaders said they are in no hurry to move on a competing raft of tax extenders. Rep. Patrick Tiberi (R-Ohio), who chairs the Ways and Means subcommittee with jurisdiction over the issue, said the House will not extend the measures until after the elections.

“Chairman [Dave] Camp’s [R-Mich.] goal has been to have a package after the election, and that’s what we’re working toward,” he said. “Rather than what they’ve done, extending them en masse, we want to go through a process by which we try to separate extenders on merit.”

The committee is reviewing each extender individually, he said.

Chief Deputy Majority Whip Peter Roskam, who also sits on the Ways and Means Committee, said the House is more immediately concerned with extending the George W. Bush-era tax rates and laying out principles for tax reform.

When the time comes to consider the extenders, though, he was optimistic about being able to sell the issue to the Republican Conference as long as the promise of tax reform remains.

“If you use these as a bridge ultimately to tax reform, that’s something that makes sense for our Members,” the Illinois Republican said. “If it’s something that’s done just for the sake of doing it, it’s not as compelling.”

A senior Democratic aide was angry over the delay.

“Sen. Coburn is throwing another one of his fits, acting a lot like my 6-year-old son when he doesn’t get his way,” a senior Democratic aide said. “We can’t let vital tax cuts that have bipartisan support — and will provide a big boost to America’s working families and our economy — fall victim to these juvenile antics.”